Patent GB-411818-A (GB)
Title: Improvements in the manufacture and production of aqueous solutions of hydrochloric and sulphuric acids
IPC: C01B7/01
Filed: 1932-12-02
Abstract: Sulphuric and hydrochloric acids are obtained by reacting a sulphuryl chloride, e.g. SO2Cl or S2O5Cl2, with water in the presence of a wetting agent, or a substance which under the action of a sulphuryl chloride is converted into a wetting agent.  If restricted quantities of water or aqueous hydrochloric or sulphuric acid is employed in the process, gaseous hydrochloric acid and 60 per cent aqueous sulphuric acid may be obtained.  Hydrochloric acid gas under pressure is obtained by working in a closed system.  The gaseous acid may be washed free from sulphuryl chlorides by contact with the aqueous reactant preferably in counter-current.  The wetting agents referred to are those permanently stable to acids e.g. sulphonic acids such as benzyl-, butyl-, iso- or diisopropyl-naphthalene sulphonic acids, or naphthalene sulphonic acids condensed with formaldehyde or salts of these acids, and esters or amides derived from fatty acids or sulphonated fatty acids by combination with hydroxy-alkyl sulphonic acids such as isothionic acid or taurines or salts of these acids and those only temporarily stable to the acids formed, e.g. sulphuric esters of alcohols of high-molecular weight corresponding to the acids of fats and oils, e.g. coconut oil.  Other suitable wetting agents are the esters of alkylol amines with fatty acids or the salts of these esters, e.g. the oleic ester of triethanolamine or the formate of the stearic ester of tri-ethanolamine.  Substances which by the action of sulphuryl chlorides are converted into wetting agents comprise alcohols, aldehydes, carboxylic acids or esters, and unsaturated or aromatic hydrocarbons of high molecular weight or their chlorine derivatives, specific examples being lauric acid, oleic acid, oleyl alcohol, fats, sugars, dextrine, starch, bitumen, benzene and its homologues and chlorine derivates.  The wetting agents may be added to the sulphuryl chloride or to the water or to both. The substances convertible into wetting agents are preferably added to the sulphuryl chloride.  The reactants may also be brought together in a column packed with Raschig rings or in an autoclave under pressure.  The aqueous acid products may be employed for etching or, especially, the preservation of green fodder in silos, the presence of the wetting agent facilitating the penetration of the acid.  If a temporarily stable wetting agent is employed it will decompose during the storage of the fodder.ALSO:In a process for obtaining solutions of acids by mixing sulphuryl chloride with water, the following wetting agents are used:--butyl- or iso-propyl-naphthalene sulphonic acid, naphthalene sulphonic acid condensed with formaldehyde or salts of these acids, substances of which the basis is a higher fatty acid (e.g. esters or amides derived from sulphonated fatty acids) on the one hand and hydroxyalkyl sulphonic acids (e.g. isethionic acid or taurines) or salts of these acids on the other hand, sulphuric esters of alcohols of high molecular weight corresponding with the acids of fats and oils (e.g. coconut oil), esters of alkylol amines with fatty acids or the salts of these esters (e.g. the oleic ester of triethanolamine or the formate of the stearic ester of triethanolamine).  The action of the sulphuryl chloride on some substances forms wetting agents, e.g. alcohols, aldehydes, carboxylic acids or esters and unsaturated or aromatic hydrocarbons of high molecular weight or their chlorine derivatives, specific examples being, lauric acid, oleic acid, oleyl alcohol, fats, sugars, dextrine, starch, bitumen, benzene and its homologues and chlorine derivatives.